This is an abbreviated transcript of the closing words of Philip K.
Dick's speech given at the 1977 Metz Sci-Fi Convention, where he is
describing his creative process in his 27 years of writing science
fiction novels:

"At no time did I have a theoretical or conscious explanation for my
preoccupation with these pluriform pseudo-worlds. But now, I think I
understand. What I was sensing was the manifold of partially-actualized
realities lying tangent to what evidently is the most actualized reality
- the one which the majority of us agree on by 'consensus gentium'
[Latin for the "agreement of the people"]...

"I wrote out these dreams in novel after novel; to name two in which
this prior ugly present obtained most clearly, I cite the man in the
High Castle and in my 1974 novel about the US as a police state called
'Flow My Tears, the Policeman Said.' I'm going to be very candid with
you. I wrote both novels based on fragmentary residual memories I had of
such a horrid slave state world.

"People claim to remember past lives. I claim to remember a different -
very different - present life. I know of nobody who has ever made this
claim before but I rather suspect that my experience is not unique. What
perhaps is unique is my willingness to talk about it. We are living in a
computer-programmed reality and the only clue we have to it is when
some variable is changed and some alteration in our reality occurs. We
would have the overwhelming impression that we were living the present
deja vu - perhaps precisely in the same way, hearing the same words,
saying the same words - I submit that these impressions are valid and
significant. And I will even say this: such an impression is a clue
that, at some past time point, a variable was changed - reprogrammed as
it were - and that because of this, an alternative world branched off."